1. Field of the Invention
The present invention relates to an apparatus (finisher) for bundling sheets sent from an image forming apparatus, thereby carrying out, for example, staple processing and a waiting tray for use in the post-process apparatus.
2. Description of the Related Art
A post-process apparatus comprises: a processing tray for bundling sheets sent from an image forming apparatus, thereby carrying out, for example, staple processing, and ejecting the processed bundles of sheets; and a storage tray for holding the ejected bundles of sheets. A staple processing speed of the post-process apparatus is slow as compared with an image processing speed of the image forming apparatus. Thus, if a sheet is directly sent to the processing tray, a sheet to be staple processed next is transported while a preceding sheet is staple processed. In order to prevent this problem, conventionally, a buffer mechanism for adjusting a carrying-in timing of a sheet at a front stage of the processing tray is proposed.
Japanese Patent Document 1: Japanese Patent No. 2583594 discloses a mechanism for retaining sheets is provided at a transport passage for sending sheets sent from an image forming apparatus to a processing tray. However, in this case, there is a need for increasing the transport passage in length, and, as a result, the post-process apparatus is likely to be large in size.
Japanese Patent document 2: Jpn. Pat. Appln. KOKAI Publication No. 2000-72321 discloses a mechanism that an extension tray is retractably provided on a sheet alignment tray of a staple unit; and, when a recorded sheet is ejected from an image forming apparatus, the extension tray is fed out from the sheet alignment tray, and the ejected sheets are stacked on these trays. However, the patent document 2 discloses a technique relating to the sheet alignment tray of the staple unit which is technically different from that of the present invention relating to a waiting tray. Therefore, advantageous effect of the present invention cannot be attained.